Argentine ants usually build shallow nests outdoors, around landscaping features or things like stored bricks, wood piles or mulch. They especially like the moist soil around building foundations. These ants sometimes enter homes through small cracks and prefer to build nests in insulation or within walls. More often, they search for food indoors and then return to an outdoor nest.

Argentine ants can build giant colonies that span multiple buildings. They are successful at spreading because their colonies contain multiple queens and don’t fight with other colonies, making their expansion exponential.

The most noticeable sign of an infestation is the trail of ants that will quickly move to an open food or water source. Following the trail to its entry-point will help you determine where the ants are coming from, but it’s not easy to find their nests. Check any shrubs or garden plants around the exterior of your home—you might find ants together with aphids or other insects that secrete “honeydew,” a sweet byproduct that these bugs produce as they eat plant sap.

Argentine worker ants forage in homes for sugary foods. They’re active during the day and night, frequently moving their colonies to new nests in new locations. They are particularly resilient pests because of their lack of a fixed home and having many queens per colony. Like other ants, they use pheromone trails to track each other and find their way to food and water sources.

Argentine ants are aggressive toward other species, invading habitats and pushing out other ants. Despite this aggression, they are not competitive with other Argentine colonies, sometimes even combining with them. You’ll likely see worker ants accompanying aphids or mealybugs on plants to feed on their honeydew.

Water attracts Argentine ants to houses, causing them to search for entrances through small cracks in walls or the foundation, loose windows and pipe entrances. The mobility of their colonies means that they can quickly enter a building in large numbers.

Food also attracts ants to houses, but not only those crumbs left out on the counter. Since worker ants feed on honeydew from aphids and other insects, the presence of these other pests can bring Argentine ants. The ants communicate with pheromone trails, so if they find a source of food indoors, they can quickly tell the rest of the colony where it is.

Ants will look for entrances to homes during hot, dry weather, following the condensation on pipes into a house as they search for moisture. They might also be driven indoors by heavy rains that flood their outdoor nests. In either case, you can find Argentine ants near electrical outlets, on bathroom ceilings and in the kitchen.

Argentine ants are extremely resilient and, though they’re easy to kill with store-bought sprays, their colonies are much more difficult to remove. Controlling them effectively requires professional help. However, there are some tips to help prevent these ants from entering your home:

1. Remove piles of wood, bricks, stones, leaves and other landscaping debris from around your home.

2. Keep any layer of mulch around your house shallow to make it less attractive to ants.

3. Repair leaking pipes and direct gutters away from walls.

4. Thoroughly inspect your walls and floors for cracks and seal any that you might find.

5. Keep shrubs and trees trimmed away from your home and check them for aphids.

6. Begin a regular treatment plan with Aptive Environmental to control ants all year long.